Two-cycle engine carburetion system



April 22, 1941. w. A. LUNDELL 2,239,239

I TWO-CYCLE ENGINE CARBURETION SYSTEM 'Filed Feb. 27, 1940 iiipii uiiiii[m Patented Apr. 22, 1941 UNITED STATES PATENT OFFICE TWO-CYCLE ENGINE OARBURETION SYSTEM William Alfred Lundell, Tacoma, Wash. Application February 2'], 1940, Serial No. 321,051

3 Claims. 123-73) My invention relates to improvements in twocycle engine carburetion system, and the objects of my improvements are: first, to eliminate the fuel leakage around the pistons and out of the exhaust ports; second, to more thoroughly atomize the fuel in its very short travel into the combustionchamber, thereby saving fuel; third, to eliminate carburetion icing trouble in aviation use; fourth, to cause higher volumetric efilciency; fifth, to cause avery easy starting motor. I atthroughout the several views.

The structure I embodies the manually operated raw-fuel varying valve lever I and needle 6, which has its seat on the raw-fuel let ll. It also embodies the raw-fuel jet l'l opening and closing disc is, which is rocked by the shaft ii and the shaft end 3. The shaft ii is rocked by the action of the cam Iii on the crank shaft N through tappet l3, push rod l2, androcker 9. Fuel pipe I supplies raw-fuel to jet ii.

The action of this system is as follows: The piston 2, in its travel on its up stroke, creates a vacuum in the crank case It, which, having a communicating passage through ports 4 and .piston ports 22, creates a vacuum in the chamber 23. while the piston 2 istraveling up on its up stroke, the crank shaft ll has turned cam 7 l so as to lift tap'pet l3 and the push rod I2; and it also has rocker 9, which in turn, has

' turned shaft Ii through a short are as in Fig. 3 (from I 8 dotted to I 8) thereby opening the rawfuel Jet I'I. As there is avacuum in this chamber 23 (previously created), a raw-fuel charge '1 tain these objects by the mechanism illustrated Q is drawn into chamber 23. 'Now, as the piston turned the cam l5 so that the tappet l3, push rod i2, and rocker 9 have returned to their lowered positions by the action of the spring ill.

7 The above action rocks shaft ll, end 3, and let .2 startson its down stroke, the crank II has uncoverspexhaust port it. The exhaust port ated rawTuel jet, fuel control valve.

' WIIHAM I! having cleared the cylinder of burnt gases and the further travel of piston 2 on its downward stroke uncovers by-pass ports 4. At the same time piston ports 22 line up with ports 4, there-- by creating a free passage for the pure air from crank case it into combustion chamber 24..

Now as pure air, in its rush up "into chamber 24, travels at a high velocity, thereby,picking up the raw-fuel charge (that was drawn into the lay-pass 22 previously on the up stroke of piston 2) and atomizing the raw fuel by the blaster air on its travel into the combustion chamber 24.

Pure air is drawn into the crank case it by the piston 2, creating a vacuum in the crank case it on said pistons up-stroke until it uncovers and opens the" air intake ports 20 wide open. Then air rushes in until piston 2 on its down stroke covers ports 20 looking the air in crank case it. It should be noted that there is no. carburetor nor any other obstruction covering the ports 20. thereby increasing the volumetric efllciency of the engine.

I do not wish to be limited to the precise details of construction as shown. as changes in construction can be made without departing from the principle of my invention.

I claim:

1. In an internal combustion engine, the 'combination of a cylinder and a crankcase, a bypass connecting the cylinder 'and crankcase for the p of scavenging air from the crankcase'to thecylinder. a liquid fuel jet opening into said bypass. a valve seat for said fuel let, a sliding disc on said: valveseat and means for operating said sliding disc so that the liquid fuel is m- .Jected into the air as it passes from the crank- ,case'to the cylinder.

2. The combination. in a two-cycle engine mechanically operated by-pass structure raw fuel metering valve, a sliding raw fuel cut off or metering disc. a sliding raw fuel metering disc seat, mechanical means for operating the raw fuel cut on disc, a raw fuel jet, means for manually controlling fuel to'the raw fuel jet.

3. The combination in a two-cycle engine bypass structure mechanically operated rawr fuel metering jet, a raw fuel meteringdisc, a raw fuel meteringdiso seat, mechanical means to operate the raw fuel metering disc from engine crank shaft, a raw fuel let, a manually oper- A. LUN'DELL. 

